2.Complex I (NADH-CoQ reductase) composition:flavoprotein (FMN)iron-sulphur protein (Fe-S) function:electron tansfer from NADH to CoQ(ubiquinone) NADH- FMN;Fe-S CoQ NADH H FMN CoQ NAD X FMNH, XX CoQH2
2. ComplexⅠ （NADH-CoQ reductase） ◆ function: electron tansfer from NADH to CoQ(ubiquinone) NADH FMN; Fe-S CoQ ◆ composition: flavoprotein（FMN）、iron-sulphur protein（Fe-S） NADH + H+ FMN Fe2+S CoQ NAD+ FMNH2 Fe3+S CoQH2
Structure of NAD+and NADP+ Nicotinamide NH2 CONH2 0 H H CH2—0-P-0-P-0-H2C OH HO OHOH H H H H H OH OR R=H:NAD+;R=HPO:NADP+
Structure of NAD+ and NADP+ R=H: NAD+ ; R=H2PO3 : NADP+ Nicotinamide
Conversion between NAD+(NADP+)and NADH+H+ (NADPH+H+) HH CONH2 CONH2 +H+H++e≥ +H+ R R NAD+or NADP+ NADH or NADPH
Conversion between NAD+（NADP+） and NADH+H+ （NADPH+H+） or or
FMN (flavin mononucleotide) CHOPO H-C-OH H-C-OH R H-C-OH H'te H.C HC、 isoallo H xazine H.C FMN FMN· FMNH2
FMN（flavin mononucleotide） isoallo xazine
Fe-S prosthetic group ini iron-sulphur protein carries the reaction: Fe2+Fe3++e Fe SCH2---- 一一一一 -CH2 Fe ---一-CH2—S Fe FeS—CH2----- Sindicates inorganic sulphur
Fe-S prosthetic group in iron-sulphur protein carries the reaction: Fe2+ Fe3++e - Ⓢ indicates inorganic sulphur